1. Field of the Invention
The present invention relates to vehicle occupant restraints and more particularly to a "smart" airbag apparatus capable of modulating inflation characteristics in response to collision and occupant parameters.
2. Description of the Related Art
Many vehicles on the road today include airbags installed in steering wheels, dashboards, and more recently, doors. These airbags are designed to protect a vehicle occupant against both front and side impact collisions by rapidly inflating the airbag to absorb much of the collision energy that would otherwise be transferred to the occupant.
Such conventional airbags are inflated based on a single threshold test: if a predetermined vehicle deceleration occurs in a collision, airbag inflation is triggered. Thereafter, airbag deployment occurs at a predetermined inflation rate. Both the triggering threshold and the inflation rate are not modified based on the type of vehicle collision, or the many different occupant variables, such as occupant weight, occupant position at the moment of impact, etc.
This inability to modulate inflation characteristics has resulted in serious injuries, even deaths, because of the existence of airbags in the vehicles had not been equipped with. This is because the explosive force of inflating airbags impacting occupants, particularly infants, the elderly, and those not wearing seat belts, can be more harmful than the accidents would otherwise have been.
Therefore, a need exists for a "smart" airbag apparatus which provides modulated airbag deployment based upon dynamics of the collision and occupant parameters.